Still, some of the marchers remained wary of the new president.

Kathleen Crank, 19, a sophomore at Benedictine College in Atchison, Kan., traveled on a five bus caravan of 260 students to come to the march. She said she was happy to have a president who would oppose abortion but wasn’t excited about much else about Mr. Trump. She said she waited until the last minute and decided not to vote for either him or Hillary Clinton.

“Their stance on abortion is probably the only issue I’m glad about for this administration,” she said. “I’m glad that after eight years of reading Obama’s tweets celebrating Roe v. Wade, I’m glad we finally have an administration that is recognizing we need to cut funding for abortions in other countries and bringing it back down to the state level.”

Ms. Crank also said she saw abortions as less about religion than about preserving the rights of unborn children. “It’s more a social justice issue for unborn babies than a religious one to push an agenda,” she said. “Everyone should be able to live their life and live it however they want to.”

Annette Saunders, 60, drove five hours with her husband from Norwalk, Conn., to volunteer with Save the Storks, a group that opposes abortion, and to hand out signs that said, “For those who can’t.” Though she voted for Mr. Trump, Ms. Saunders said she agonized over the decision because she found him to be “crass” and was frustrated by the tape of him using vulgarities to talk about women.

“I was concerned but I felt like God told me to vote for Donald Trump,” she said. “He is standing up for pro-life and his vice president certainly is and I’m excited about seeing a turnaround.”

Young voters say why they turned to Trump